Conveyer belt support



Sept. 18, 1951 w. STAACKE 2,568,174

CONVEYER BELT SUPPORT Filed June 25, 1948 IlIIIl lliilI| Patented Sept. 18, 195i CONVEYER BELT SUPPORT Charles Staacke, Akron, Ohio, assignor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application June 25, 1948, Serial No. 35,197

6 Claims.

' This invention relates to rotatable supports for-conveyor belts and is especially useful in supporting a horizontal or inclined return reach of a conveyor belt.

Where conveyor belts have been used for transporting broken or crushed rock, coal, granular or powdered materials, the upperreach of the belt has beensupported in troughed shape by groups of cylindrical idler rollers, and the return reach of the belt has been supported on flat faced cylindrical idler rollers. It has been found that the return reach of the belt tends tov shift laterally causing its margins to contact edge guides and to wear rapidly due to contact therewith. Such lateral shifting has been found especially severe where powdered material has built .up on the under side of the belt due to the presence of moisture, thereby providing an uneven surface for contact with the idlers.

It has been proposed to support the return reach of the belt upon a series of laterally spaced apart narrow faced rollers of equal diameter between which it was expected that the belt would flex laterally and thereby discharge accumulations of material on its under face but while some improvement in discharge of adherent material has resuled, it has also been found that the margins of the belt tend to flex downwardly be- .tween the narrow rollers thereby bringing a margin of the belt into contact with a side of a flanking roller with consequent wear and increased lateral fiexing Of the margin.

It is an object of the present invention to overcome the foregoing and other difficulties by providing a wide support for the belt at its margins while nevertheless providing for escape of adhered material at the center of the belt.

Other objects are to provide for support of the return reach of the belt in reversely troughed condition, to reduce lateral shifting of the belt, and to reduce wear of the belt.

These and other objects will appear from the following description and the accompanying drawings.

Of the drawings:

Fig. 1 is a side elevation of a conveyor belt and the supporting mechanism in which the supports for the return reach of the belt are constructed in accordance with and embodying the invention.

Fig. 2 is a sectional view thereof, taken on line 2-2 of Fig. 1 showing a set of supporting rollers,

Referring to the drawings, the numeral l0 designates a conveyor belt trained about pulleys ll, [2, one of which may be the driver. The upper or material supporting reach M of the belt, is supported at intervals therealong by troughing idlers l5. The lower or return reach [6 is supported at intervals therealong by reverse troughing idlers l1 corresponding to the invention and shown in Fig. 2.

Each ofthe reverse troughing idlers l1 comprises a series of narrow rollers l8, I9, 20 arranged in spaced apart relation on a supporting shaft 2| rotatably mounted in bearings 22, 23. The roller H), at the center of the belt is larger in diameter than the rollers'lB, 20 to support the center of the belt in reversely troughed condition. Each of the rollers I8, I9, 2!] has a web 25 of rigid material such as metal, which is secured to the shaft 2! as by a set-screw 26, and a resilient tread 21 of vulcanized rubber or other rubber-like material for contacting the belt. Preferably the treads of these rollers are of convex cross section, as shown to provide a narrow contact with the belt. While three of the narrow rollers have been shown it will be understood that the number of rollers will depend upon the Width of the belt and that more will be employed with very wide belts. The rollers are graduated in diameter from the center line of the belt toward each margin so as to support the belt at the desired lateral curvature.

For supporting the belt inthe region of its lateral margins, a pair of wide faced conical rollers 30, 3| are employed, arranged with their smaller ends toward the margins of the belt and spaced inwardly thereof by at least one inch so that the margins of the belt overhang the rollers. Each of the rollers 30, 3i has a tubular hub 32 to which is secured a resilient tread 33 of rubber or other rubber-like material. The hub 32 is rotatably mounted about the shaft for free rotation, as by being mounted on ball bearings 34, 35. The treads of the conical rollers are usually about four or five inches wide so that should any shifting of the belt take place, the margins of the belt cannot flex downwardly to engage a radial surface of the rollers. The conical rollers are of such size and taper as to continue the desired curvature of reverse troughing The support of the return reach of the belt in reversely troughed condition tends to overcome any tendency for the belt to shift laterally in much the same manner as a crowned pulley tends to cause a belt thereon to run to the center.

To break up the continuous contact of the conical rollers with the belt surface, the treads thereof may be formed with alternate circumferential ridges 40 and grooves 4| as shown in Fig. 3. The ridges are relatively close to each other and have inclined side faces so that the margin of the belt does not sink into one of the grooves. These ridges and grooves may be of helical formation as-in Fig. -2 where the roller-30 has left hand ridges and grooves and=the.roller 3! has right hand ridges and grooves.

Where the weight of the belt upon the rollsis equal, the forces exerted on the belt. Joytheinclined ribs and grooves will act in opposite directions and will equalizei'each other. As.,the large ends of the rollers will Joe drivencat a higher surface speed than the small ends thereof some slippage between the rollers-and; the belt will occur resulting in a wiping action of the helical ribs relative to the surface of theibelt and exerting a force tending to move the belt laterally toward the centerof the beltas; it passes thereover.

Should the beltrun toene sidegthe excess weight upon the rollergat that.sideyvillcause a greater force to be exerted by; that roller than-by t opp i I'0 31t6 ldin t qa setheb l -lt return to thecenter.

.The reverse troughing ,of thebelt.;.0n the ;return reach presents av convex upper; surface so that material falling on the, return- -reach will be shed tothe sides.and will-not follow the j-bQlt for contacting the lower face .of the return reach said marginal rollers shaving faces convex in cross-section providinglsubstantiallyline contact with the belt, and-the; treads. .of the. rollers of a set collectively presenting an arcuatesupport for contact with the ,belt .to support the belts in.- reversely troughed condition-said marginal. rollers beingspaced inwardly of the .belt. from its margins so that overhang of the. margins .of thebelt is provided.

2. A sup ort for the return reach of.a-belt,said support comprising aset of laterallyspaced coaxially mounted rollers having resilient treads'for contacting the lower face of thereturn reach of the belt for supporting 'it, the marginal rollers of said set having conical tread .surfaces broader than the rollers therebetweenpand the treads .of the rollers of a set collectively presenting. a convex contact with the-belt to-"support the belt-in reversely troughedconditiomsaid marginal rollers having belt. contacting surfaces comprising.

axially mounted rollers having resilient treads for contacting the lower face :of theretur-n reach of t be ppo t n it: t e mar inal; ro ers .o

4 said set having conical tread surfaces broader than the rollers therebetween, the rollers between said marginal rollers having faces convex in cross-section providing substantially line contact with the belt, and the treads of the rollers of a set collectively presenting an arcuate support for contact with the belt to support the belt in reversely' troughedcondition,said marginal rollers being freely rotatable relative to the rollers there- :for contacting. thezlower face of the return reach of -thebelt forsupporting it, the marginal rollers of said set-having conical tread surfaces broader than the rollers therebetween, and the treads of the rollers of a set collectively presenting a convexcontact with the belt to support the belt in reversely troughed condition, said marginal roll- :ers .having w-belt contacting surfaces comprising narrow; helical grooves, the .ribs :and grooves/of one marginal roller being. .of. Opposite inclination to the ribs and grooves of the other marginal roller.

15. zAsupport for! the return reach of. atroughed conveyor belt, said support comprising arset of laterally spaced coaxially. mounted rollers having resilient/treads for contactingthelower face-of thereturn reach. ofthe belt for supporting it, the marginalrollersof said set-having, conical tread surfaces broader than the rollers therebetween, andthetreads of the rollersof a set col- =lectively presenting a convex contactwith thebelt of a curvature supporting said reach iii-reversely troughed condition providing equal tensioningof the belt throughout its width, said-marginal roll- .ershaving helically grooved treads of opposite hand at opposite margins of-the belt andbeing spaced inwardly from the margins ofthe-belt to provide overhang of the belt at its-margins, and said marginal rollers being rotatable relative'to the rollers therebetween.

6. A support-'for'the return reach of a-belt, said support comprising a rotatable shaft, a set of laterallyspaced rollers coaxial ofsaid shaft and supported thereby beneath thereturn reach of the belt, said shaft extending transversely of said return reach, the marginal rollers of said set being-mounted for free rotation about said shaft in the regions of the margins of the-belt and being generally conical in shape, the rollers intermediate said marginal rollers having tread surfaces convex in cross-section-for contacting the lower face -of the belt, said intermediate rollersbeing of largerdiameter than said marginal rollers, and the-treads of the rollers of the set collectively presenting aco nvex support transversely of the belt for supporting the return reach of the belt in reversely troughed condition.

CHARLES STAACKE.

REFERENCES CITED The following referencesareof record inthe file of. this patent UNITED .S'llAT-ES PATENTS sNumber Name Date 714,812 Mann et al. Dec.2, 1902 :1-,'7'73',621 .Hopkinson Aug. 19, 1930 -2 ;05.2,900 searlessetlal. :Sept. 1, 1936 

